JP3943548B2 - Electroluminescence device - Google Patents

Description

  The present invention relates to electrode design for electronic devices. In particular, the invention relates to improvements in electrodes for electronic and optoelectronic devices.

  Electronic and optoelectronic devices such as organic light emitting diodes (OLEDs) are known in the art. OLEDs, also called organic electroluminescent (EL) devices, generally include an organic electroluminescent (light emitting) material sandwiched between two electrodes. The organic electroluminescent material is generally a multilayer structure including an electron transport layer, an electroluminescent layer, and a hole transport layer. When an electric current is passed, the organic electroluminescent material emits light generated by recombination of electrons and holes in the organic material. However, organic luminescent materials are sensitive to impurities, oxygen and humidity. Furthermore, in some electronic or optoelectronic devices, the electrodes affect the strength, stability and reliability of the device. Organic electroluminescent devices (materials and structures) are known in the art, for example as disclosed in US Pat. No. 4,356,429, US Pat. No. 5,593,788 or US Pat. No. 5,408,109.

  Since multilayer device architectures are now well understood and widely used, the remaining condition that limits the performance of OLEDs is the electrode. The major figure of merit of an electrode material is the position of the electrode Fermi energy relative to the relevant organic molecular energy level. In some applications, it is further desirable that the electrode assist in light extraction. In order to achieve long-term stability of the electroluminescent device, the electrode must also be chemically inert to the adjacent organic material.

  Much attention has been paid to the cathode, mainly because it is the low work function metal that provides good electron injection, and the low work function metal is simultaneously chemically reactive and air. This is because it oxidizes immediately, limiting the reliability and lifetime of the OLED. Much less attention has been paid to optimizing anode contacts, which means that traditional ITO anodes generally outperform cathode contacts and reduce excess of holes. To bring. Due to this excess and the convenience associated with the conductivity and transmittance of indium-tin-oxide (ITO), anode improvements have not been pursued as aggressively as cathode improvements.

  As organic electroluminescent devices were used, problems with sufficient hole injection and operational stability occurred. Some problems were alleviated by the fluorocarbon treatment of the device anode. US Pat. No. 6,127,004 relates to a method of forming an electroluminescent device, the method comprising providing a substrate having a top coating of material comprising an anode comprising indium-tin-oxide (ITO); Providing an amorphous conductive layer on the anode by supplying a fluorocarbon gas to a radical source cavity and depressurizing the fluorocarbon to a range of 0.1 to 20 mT. In addition, an RF field across the fluorocarbon gas in the radical source cavity is applied to form a plasma with CFx radicals, and the CFx radicals are deposited on the anode to form an amorphous CFx conductive polymer layer on the anode. To do. Next, a plurality of layers including at least one organic electroluminescent layer is formed on the amorphous CFx conductive polymer layer, and a cathode is formed on the electroluminescent layer.

  U.S. Pat. No. 6,208,075 also relates to an organic electroluminescent device having a conductive fluorocarbon polymer layer disposed on the anode, and U.S. Pat. No. 6,208,077 is a thin non-conductive fluorocarbon. The polymer layer is described. The above-mentioned fluorocarbon polymer layer is applied because of its transport properties, and therefore the fluorocarbon polymer layer acts as a hole injection layer. The fluorocarbon polymer layer is preferably deposited on an anode containing oxygen (eg, ITO), and device performance becomes unstable when other materials are used.

  The international application having international publication number WO 99/39393, currently assigned to the assignee of the present application, relates to an organic light emitting device having an anode, a barrier layer, an anode modification layer, an organic region and a cathode in this order. The anode improvement layer is in direct contact with the organic region. The barrier layer is arranged to separate the anode modification layer from the anode, but this layer interferes with injection if the barrier layer exhibits barrier properties.

  The optoelectronic device can operate as a top emission device or as a bottom emission device. A bottom emission device is also referred to as a backemission device. In bottom emission devices, the anode must be nearly transparent so that the emitted light can pass through the anode. Indium-tin-oxide (ITO) is widely applied as an anode because it forms a substantially transparent layer. The disadvantage of ITO is that it reacts somewhat with the layers above it, such as hole transporting organic materials. This shortens the lifetime of the device. In order to avoid shortening the lifetime, a buffer layer, eg CuPc, is usually used between the anode and the organic material, but the buffer layer is highly resistive and hinders injection. As mentioned earlier, the buffer layer can be omitted by using a fluorocarbon polymer layer.

  Molybdenum or platinum is applied to the top emission device. These materials are opaque and have strong light absorption. The reflectivity of platinum is not optimal. Silver (Ag) and aluminum (Al) have high reflectivity, but have a low work function and are therefore unsuitable as anode materials. In general, the most suitable anode material is a material having a high work function. Low work function materials such as Al are generally chemically very active when coated with a buffer layer such as CuPc, and therefore such materials are not suitable for forming an anode. Furthermore, the combination of such materials and fluorocarbon polymer layers also does not provide reliable performance, thus making the device useless.

In view of the foregoing, there remains a need for improved electrode structures for electronic and optoelectronic devices that exhibit long-term stability and high efficiency.
US Pat. No. 4,356,429 US Pat. No. 5,593,788 US Pat. No. 5,408,109 US Pat. No. 6,127,004 US Pat. No. 6,208,075 US Pat. No. 6,208,077 International publication number WO99 / 39393 C. Tang, SID Conference Proceedings San Diego, 1996 C. Adachi et al., Applied Physics Letters, 66, 2679, 1995 B. Borsenberger and DS Weiss, Organic Photoreceptors for Imaging Systems, Marcel Dekker, 1993 Y. Kuwabara et al., AdvancedMaterials, 6, 677 pages, 1994 Y. Shirota et al., Applied Physics Letters, 65, 807, 1994 International Symposium on Inorganic and Organic Electroluminescence 1994, Hamamatsu, 42 W. Wakimoto et al., International Symposium on Inorganic and Organic Electroluminescence 1994, Hamamatsu, 77 C. Tang, SID Conference Proceedings San Diego, 1996, 181 E. Staring, International Symposium on Inorganic and Organic Electroluminescence 1994, Hamamatsu, 48 T. Oshino et al., Sumitomo Chemicals, monthly report, 1995

  Accordingly, it is an object of the present invention to provide an improved electrode structure for electronic devices including organic materials and displays based thereon.

  According to the present invention, a first electrode substantially having a conductive layer, a nonmetallic layer formed on the conductive layer, a fluorocarbon (fluorinated carbon) layer formed on the nonmetallic layer, An electronic device is provided that includes a structure formed on the fluorocarbon layer and a second electrode formed on the structure.

  The electronic device can further comprise a buffer layer between the conductive layer and the non-metallic layer. Such a buffer layer advantageously reduces the reaction between the first electrode and the other layers. In particular, the oxidation process can be prevented.

  In a preferred embodiment, the conductive layer includes aluminum (Al). Aluminum is usually very reflective and highly reactive. However, if a non-metallic layer or a non-metallic layer and the aforementioned buffer layer are placed on a conductive layer, an electroluminescent (light emitting) device having excellent properties and characteristics can be designed.

  The non-metallic layer can include an oxide. Oxides are materials that can be used abundantly or that can be formed from many materials or compounds. The oxide can be based on a material selected from one of the following groups: 3d transition metal group, IIIA group, IVA group, rare earth metal group, or combinations thereof.

When the non-metallic layer is an oxide (also referred to as a foreign oxide) that is different from the potential oxide formed by the conductive layer, the electrical and optical properties of the electrode, such as implantation and The advantage is that the transparency can be adjusted. For example, when the conductive layer is made of Al, the oxide that may be formed or generated by the conductive layer is aluminum oxide. Aluminum oxide has a higher resistance than, for example, nickel oxide (NiO _x ). Accordingly, when NiO _x is used as a foreign oxide to form a nonmetallic layer, better hole injection characteristics than aluminum oxide can be obtained. The combination of a highly reflective conductive layer and a non-metallic layer that supports hole injection also provides a highly reliable and greatly improved electroluminescent device with improved light output.

  Depending on the nature of the conductive layer, the thickness of the non-metallic layer is in the range from monolayer to 20 nm, which is advantageous because electronic devices exhibit excellent long-term stability and high efficiency. In electroluminescent devices (OLEDs), eg active drive devices, the layer thickness is often related to the magnitude of the drive voltage.

  The conductive layer can include a metal, a semiconductor, or an organic conductor. Further, the conductive layer can include a light reflecting material. A preferred conductive layer material or electrode material is aluminum (Al) or silver (Ag). These materials become clear (effective) when oxides or foreign oxides are used as the non-metallic layer on the conductive layer.

  The conductive layer can form a mirror-like surface. This means that the anode acts as a mirror, reflecting the emitted light and enhancing the light output. This concept applies to both top-emission devices and bottom-emission devices.

  It should be understood that the term “optoelectronic device” refers to any device that acts as an electro-optic converter or an opto-electrical converter, or equipment that uses such a device in operation.

  The electronic device can comprise a substrate in contact with the conductive layer or structure. The substrate can be any material including glass, a transparent material for top emission devices, Si, plastic, an opaque material for bottom emission devices. This substrate can be used as a base for forming electronic devices.

  The electronic device can be part of an electroluminescent device, transistor or sensor. This indicates that this electrode design can be widely used. However, this structure is not limited to the aforementioned applications. Furthermore, this structure is not limited to use only with organic structures, but can also be used with the following structures: organic / inorganic, organic-inorganic hybrids or inorganic structures. Furthermore, electrode designs with this structure can be applied to a wide variety of electronic and optoelectronic applications.

  The invention further relates to a method of forming this electronic device. The method includes providing a conductive layer that acts as a first electrode, forming a non-metallic layer on the first electrode, depositing a fluorocarbon layer on the non-metallic layer, Forming a plurality of layers as a structure on the fluorocarbon layer; and forming a second electrode on the structure.

  In the following, preferred embodiments of the present invention will be described in an exemplary and detailed manner with reference to the accompanying schematic drawings.

  These drawings are presented for illustrative purposes only, and not necessarily to scale, actual examples of the invention are presented.

  Although the present invention is applicable to a wide variety of electronic and optoelectronic applications, it will be described herein with a focus on applications in organic electroluminescent devices, ie organic light emitting diodes (OLEDs) and organic transistors.

  Prior to describing embodiments of the present invention, reference will be made to the configuration of prior art electroluminescent devices.

  FIG. 1 shows an organic electroluminescent device 100. The device has a substrate 102 on which an indium-tin-oxide (ITO) anode 104 is disposed. The substrate 102 and the ITO anode 104 are light transparent. A polymer layer 108 is disposed in direct contact with the ITO anode 104. An organic light emitting structure 110 is formed between the ITO anode 104 and the cathode 120 coated with the polymer layer 108. The organic light emitting structure 110 includes an organic hole transport layer 112, an organic light emitting layer 114, and an organic electron transport layer 116 in this order. When a voltage is applied between the anode 104 and the cathode 120 so that the anode 104 is electrically positive with respect to the cathode 120, the cathode 120 injects electrons into the electron transport layer 116, and the injected electrons are The electron transport layer 116 and the light emitting layer 114 are traversed. At the same time, holes are injected from the anode 104 into the hole transport layer 112, the injected holes pass through the layer 112, and finally, electrons and electrons are near the interface between the hole transport layer 112 and the light emitting layer 114. Rejoin. When electrons in the conduction band radiatively recombine with holes in the valence band, photons are emitted through the light transmissive anode 104 and substrate 102, as indicated by the arrows, Visible.

  The polymer layer 108 can be formed by plasma polymerization of fluorocarbon gas in RF plasma. The fluorocarbon polymer is a polymer similar to Teflon (R) and is substantially composed of carbon and fluorine. The fluorocarbon polymer may further contain hydrogen and / or minor impurities such as nitrogen, oxygen. The thickness of this polymer layer is selected so that it completely covers the underlying conductive layer and its low conductivity does not negatively impact device performance.

  FIG. 2 shows a schematic diagram of a first embodiment of an organic electroluminescent device 200. The organic electroluminescence device 200, which is a top emission device here, has a substrate 202, on which a first electrode 204, also called an anode 204, is arranged. The anode 204 includes a layer of conductive highly reflective material labeled with M, thus providing a mirror-like surface. On the anode 204, a non-metal layer 206 substantially made of an oxide is formed. Further, a polymer layer 208 substantially made of fluorocarbon is formed on the non-metal layer 206. An organic light emitting structure 210 is formed between the non-metallic layer 206 coated with the fluorocarbon layer 208 and the cathode 220. The organic light emitting structure 210 includes, in order, an organic hole transport layer 212, an organic light emitting layer 214, and an organic electron transport layer 216. The structure described here is distinctly different from the prior art structure shown with reference to FIG. A non-metallic layer 206 is disposed between the anode 204 and the polymer layer 208.

  The polymer layer 208 is formed by plasma polymerization of fluorocarbon gas in RF plasma. Chemical vapor deposition (CVD) can also be applied.

The anode 204 includes a conductive highly reflective material layer, preferably an Al or Ag layer, thus providing a mirror-like surface. The non-metallic layer 206 includes an oxide that is different from the oxide that the conductive highly reflective material forms when in contact with oxygen or in an environment such as ITO, NiO _x , for example. Several methods for depositing the non-metallic layer 206 are described below.
-Chemical vapor deposition (CVD) including plasma chemical vapor deposition (PECVD).
-Sputter deposition (deposition) or reactive sputter deposition (eg in an oxygen environment)-Thermal evaporation-Electron beam evaporation-Oxygen plasma (plasma assisted oxidation)
-Thermal annealing in oxidizing environment-UV ozone treatment-Wet chemical oxidation-Electrochemical oxidation

  The substrate 202 is used as a base and must be electrically insulated. The device shown here is a top emission device, i.e. the generated light is reflected off the mirrored surface of the anode 204 and passes through the cathode 220 as indicated by the arrow, so the substrate can be opaque. . In this case, the cathode 220 must be light transmissive.

  The present invention is not limited to top emission devices, but can of course also be applied to bottom emission devices with all the advantages. In that case, the anode 204 must have transmission characteristics.

  When a bottom emission device or architecture is desired, the anode 204 and the substrate 202 must be light transmissive. In this case, the anode 204 suitably includes a semi-transparent material or metal film. These can include transparent conductive oxides such as indium-tin-oxide, doped tin oxide, aluminum doped zinc oxide. These materials must be suitably deposited on quartz glass or a transparent substrate 202 such as a polymer substrate of polyethylene terephthalate or polyvinyl acetate, for example.

  Various compositions can be utilized for the organic light emitting structure 210.

  Hole transport layer and hole injection layer: The following materials are suitable as hole injection layer and organic hole transport layer 212: tetraphenyldiaminodiphenyl (TPD-1, TPD-2 or TAD), NPB (see C. Tang, SIDMeeting San Diego, 1996 and C. Adachi et al., Applied Physics Letters, 66, 2679, 1995), TPA, NIPC, TPM, DEH (For these abbreviations, for example, aromatic amino groups such as P. Borsenberger and DS Weiss, Organic Photoreceptors for Imaging Systems, Marcel Dekker, 1993). Including material. These aromatic amino groups are polymerized, starburst (eg TCTA, m-MTDATA. Y. Kuwabara et al., Advanced Materials, 6, 677, 1994 and Y. Shirota et al., Applied Physics Letters, 65, 807, 1994) and spiro compounds.

  Other examples include copper (II) phthalocyanine (CuPc), (N, N′-diphenyl-N, N′-bis- (4-phenylphenyl) -1,1′-biphenyl-4,4′-diamine. ), Distyrylarylene derivatives (DSA), naphthalene, naphthostyrylamine derivatives (eg NSD), quinacridone (QA), poly (3-methylthiophene) (P3MT) and its Derivatives, perylene and perylene derivatives, polythiophene (PT), 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA), PPV and some PPV derivatives such as MEH- PPV, poly (9-vinylcarbazole) ( VK), there is a discotic liquid crystal material (HPT).

Electron transport / luminescent materials are Alq ₃ , Gaq ₃ , Inq ₃ , Scq ₃ (q refers to 8-hydroxyquinolate or derivatives thereof), and Znq ₂ , Beq ₂ , Mgq ₂ , ZnMq _2, BeMq _2, BAlq, which is another 8-hydroxyquinoline metal complexes such as AlPrq _3. These materials can be used as the organic electron transport layer 216 or the organic light emitting layer 214.

  Other classes of electron transport materials are electron-deficient nitrogen-containing systems such as oxadiazoles such as PBD (and many derivatives) and TAZ (1,2,4-triazole). ) And other triazoles.

  These functional groups can also be incorporated into polymers, starbursts and spiro compounds. Another class is materials containing pyridine, pyrimidine, pyrazine and pyridazine functional groups.

  Finally, materials containing quinoline, quinoxaline, cinnoline, phthalazine and quinaziline functional groups are well known for their ability to transport electrons.

  Other materials include didecyl sexithiophene (DPS6T), bis-triisopropylsilylsexithiophene (2D6T), azomethine-zinc complexes, pyrazine (eg BNVP), Styrylanthracene derivatives (eg BSA-1, BSA-2), non-planar distyrylarylene derivatives, eg DPVBi (C. Hosokawa and T. Kusumoto, International Symposium on Inorganic and Organic Electroluminescence 1994, see Hamamatsu, 42), cyano PPV (PPV means poly (p-phenylenevinylene)), cyano-substituted polymers such as cyano PPV derivatives.

  The following materials are particularly well suited as emissive layers and dopants: anthracene, pyridine derivatives (eg ATP), azomethin-zinc complexes, pyrazines (eg BNVP), styrylanthracene derivatives (eg BSA). -1, BSA-2), coronene, coumarin, DCM compound (DCM1, DCM2), distyrylarylene derivative (DSA), alkyl-substituted distyrylbenzene derivative (DSB), benzimidazole ( benzimidazole) derivatives (eg NBI), naphthostyrlamine derivatives (eg NSD), oxadiazole derivatives (eg OXD, OXD-1, OXD-7), N, N, N ′, N′— Tetrakis (m-methylphenyl) -1,3-dia Nobenzene (PDA), perylene and perylene derivatives, phenyl substituted cyclopentadiene derivatives, 12-phthaloperinonexithiophene (6T), polythiophene, quinacridone (QA) (Wakimoto (T) Wakimoto et al., International Symposium on Inorganic and Organic Electroluminescence 1994, Hamamatsu, 77) and substituted quinacridone (MQA), rubrene, DCJT (eg C. Tang, SIDConference San Diego Proceedings, 1996) , 181), conjugated and non-conjugated polymers such as PPV and PPV derivatives, dialkoxy and dialkyl PPV derivatives such as MEH-PPV (poly (2-methoxy) -5- (2'-ethylhexoxy)) -1,4-Fe Lembinylene), poly (2,4-bis (cholestanoxyl) -1,4-phenylenevinylene (BCHA-PPV) and segmented PPV (eg, E. Staring, International Symposium on Inorganic and Organic Electroluminescence 1994, Hamamatsu, 48, And T. Oshino et al., Sumitomo Chemicals, 1995, monthly report).

  There are many other organic materials known to be good emitters, charge transport materials, and charge injection materials, and many more will be discovered. A light emitting structure can also be formed using these materials.

  The organic hole transport layer 212 includes at least one hole transport aromatic tertiary amine. An aromatic tertiary amine is understood to be a compound containing at least one trivalent nitrogen atom bonded only to a carbon atom, wherein at least one of these carbon atoms is a ring atom of an aromatic ring. Is done. In one form, the aromatic tertiary amine can be an arylamine such as a monoarylamine, diarylamine, triarylamine, polyarylamine, and the like.

  The organic light-emitting layer 214 is composed of a luminescent or fluorescent material, or a combination of luminescent or fluorescent materials (host and one or several dopants), and electroluminescence (emission) is in this region. As a result of electron-hole pair recombination. In the simplest structure, the luminescent layer consists of a single component, which is a pure material with high fluorescence efficiency. A well known material is tris (8-quinolinato) aluminum (Alq).

The cathode electrode 220 has a low work function (for example, less than 4.0 eV) selected from alkali metals, alkaline earth metals, rare earth metals, combined compounds such as LiF / Al, Li ₂ O / Al, or alloys thereof. , Preferably less than 3.5 eV). Preferred metals are calcium or alloys such as magnesium / silver, lithium / aluminum, magnesium / aluminum. These cathode configurations provide a low work function and thus provide an increase in quantum efficiency for the device.

  The same or similar parts are indicated using the same reference numerals.

FIG. 3 shows a schematic diagram of a second embodiment of the organic electroluminescent device 201. The organic electroluminescent device 201 has a substrate 202 on which an anode 204 is disposed. A nonmetallic layer 206 is formed on the anode 204. A buffer layer 205 is formed between the non-metal layer 206 and the anode 204 . Suitable buffer layer materials are Ti, Ni, Pt or ITO. The buffer layer 205 must be a thin layer having a thickness of several angstroms to several nanometers. This buffer layer 205 reduces chemical reactions and prevents interdiffusion between the conductive highly reflective layer of the anode 204 and other layers. In particular, oxidation processes and interdiffusion processes can be avoided. Between the non-metal layer 206 and the cathode 220, the organic light emitting structure 210 as described above is formed.

FIG. 4 shows a schematic diagram of one embodiment of an organic transistor 300. The organic transistor 300 includes a substrate 302, a gate layer 330 made of metal, a gate insulating layer 340, for example, SiO, and an organic structure 310. The organic transistor 300 further includes a source electrode 320 and a drain electrode 311 disposed on the organic structure 310 as a well-known connector. In addition, the source electrode 320 includes a conductive layer 304, a non-metallic layer 306, and a polymer layer 308 that is in direct contact with the organic structure 310. In other examples , the drain electrode 311 includes a conductive layer 304, a non-metal layer 306, and a polymer layer 308 (not shown). The drain electrode 311 and the source electrode 320 may have the same structure.

Figure 5 shows a schematic diagram of an embodiment of another organic transistor 301. The same or similar parts are indicated using the same reference numerals. Another organic transistor 301 includes a substrate 302, a gate layer 330, a gate insulating layer 340 and an organic structure 310. The difference from FIG. 4 is that the source electrode 320 and the drain electrode 311 are embedded in the organic structure 310. Conductive layer 304, non-metal layer 306, and polymer layer 308 are coupled to gate insulating layer 340.

FIG. 6 shows the current-voltage relationship of the first prototype electroluminescent device (label I) and the current-voltage relationship (thick curve) of the second prototype electroluminescent device (label II) according to the present invention. It is a figure which shows luminance-voltage relationship (thin curve). Structure of the electroluminescent device of the second trial is as follows: anode structure _{Al / Al 2 O 3 / CF} x (3nm); organic light-emitting structure _{NPB (45nm) / Alq 3 (} 65nm); cathode Ca ( 15 nm). The second prototype electroluminescent device performs much better than the first prototype electroluminescent device having a known configuration, which is particularly noticeable in brightness.

FIG. 7 is a diagram showing current-voltage characteristics (thick curve) and luminance-voltage characteristics (thin curve) of a third prototype electroluminescent device having the following structure: anode configuration Al / Ni / NiO _x / CF _x (4 nm); organic light emitting structure NPB (50 nm) / Alq ₃ (50 nm); cathode Ca (15 nm). Electroluminescent device of the third trial with a non-metal layer including a buffer layer and NiO _x containing Ni indicates the character of the steeper more than 6, this electro third trial It shows the excellent performance of luminescence devices.

  FIG. 8 is a diagram showing the efficiency-voltage relationship of the second prototype electroluminescent device. This graph shows that the second prototype electroluminescent device is optimal for OLED.

FIG. 9 is a diagram in which the lifetime of the fourth prototype electroluminescent device is normalized. The structure of the fourth prototype electroluminescent device is as follows: anode structure Al / Al ₂ O ₃ / CF _x (10 nm); organic light emitting structure CuPu (10 nm) / NPB (45 nm) / Alq ₃ (65 nm) ); Cathode Ca (3 nm) / Ag (15 nm). Extrapolated lifetime, i.e. the time it takes for the device to show half of its original brightness under constant current conditions is about 28 years, which is a very reliable electroluminescent device It is shown that. The initial luminance was 88 Cd / m ² .

The following examples are presented for better understanding. For simplicity, materials and layers formed from materials are abbreviated as follows.
ITO: Indium-tin-oxide NPB: 4,4′-bis- [N- (1-naphthyl) -N-phenylamino] -biphenyl (4,4′-bis [N- (1-naphthyl) -N-phenylamino] -bi-phenyl) (hole transport layer)
Alq: tris (8-quinolinolato-N1,008) -aluminum (electron transport layer, where the light-emitting layer and the electron transport layer function as a combined layer) .
MgAg: Magnesium silver with a volume ratio of 10: 1

The organic light emitting structure was constructed by the following method.
1a) Ti is deposited on glass (substrate).
1b) Al is deposited on Ti / glass.
1c) ITO is deposited (deposited). Optionally, a Pt or Ti buffer layer may be formed between Al and ITO.
2) Insert this structure into the plasma etch / deposition equipment.
a) Oxygen plasma treatment for cleaning and oxidation (also for ITO),
b) Depositing a 3 nm thick fluorocarbon polymer by plasma polymerization of CHF ₃ gas in 13.6 MHz plasma.
3) Transfer to OLE material deposition chamber.
a) depositing a 50-60 nm thick NPB hole transport layer on the fluorocarbon polymer layer by conventional thermal vapor deposition;
b) A 65 nm thick Alq electron transport / emission layer is deposited on the NPB layer by conventional thermal evaporation,
c) deposit a 10-20 nm Ca layer on top of it,
d) A 20 nm thick MgAg layer was deposited on the Ca layer by co-evaporation from two sources (Mg and Ag).

  Any disclosed embodiment may be combined with one or more other embodiments shown and / or described. One or more features of these embodiments can also be combined.

1 is a schematic illustration of a prior art organic electroluminescent device. 1 is a schematic illustration of a first embodiment of an organic electroluminescent device. 2 is a schematic representation of a second embodiment of an organic electroluminescent device. 1 is a schematic diagram of one embodiment of an organic transistor. 1 is a schematic diagram of one embodiment of an organic transistor. It is a figure which shows the electric current-voltage relationship of a 1st prototype electroluminescent device, and the current-voltage relationship and luminance-voltage relationship of a 2nd prototype electroluminescent device. It is a figure which shows the electric current-voltage relationship and luminance-voltage relationship of a 3rd prototype electroluminescent device. It is a figure which shows the efficiency-voltage relationship of a 2nd prototype electroluminescent device. It is the figure which normalized the lifetime of the 4th prototype electroluminescent device.

Claims (11)

A substrate,
An Al anode provided on the substrate;
A non-metallic layer of Al ₂ O ₃ provided on the anode;
A fluorocarbon layer provided on the non-metal layer;
An organic light emitting structure provided on the fluorocarbon layer;
An electroluminescent device comprising a cathode provided on the organic light emitting structure. The organic light-emitting structure is NPB (4,4′-bis- [N- (1-naphthyl) -N-phenylamino] -biphenyl) and Alq ₃ (q is 8-hydroxyquinolate or a derivative thereof). The electroluminescent device according to claim 1, wherein the cathode is Ca.   The electroluminescent device according to claim 1, wherein the anode has a reflective surface. A substrate,
An Al anode provided on the substrate;
A buffer layer of Ni provided on the anode;
A non-metallic layer of NiO _x provided on the buffer layer;
A fluorocarbon layer provided on the non-metal layer;
An organic light emitting structure provided on the fluorocarbon layer;
An electroluminescent device comprising a cathode provided on the organic light emitting structure. The organic light-emitting structure is NPB (4,4′-bis- [N- (1-naphthyl) -N-phenylamino] -biphenyl) and Alq ₃ (q is 8-hydroxyquinolate or a derivative thereof). The electroluminescent device according to claim 4, wherein the cathode is Ca.   The electroluminescent device according to claim 4, wherein the anode has a reflective surface. A substrate,
An Al anode provided on the substrate;
And non-metal layer of _Al 2 _{O 3} disposed on the anode,
A fluorocarbon layer provided on the non-metal layer;
CuPc (copper (II) phthalocyanine), NPB (4,4′-bis- [N- (1-naphthyl) -N-phenylamino] -bi-phenyl) and Alq ₃ (q Is an organic light-emitting structure having 8-hydroxyquinolate or a derivative thereof;
An electroluminescent device comprising a cathode provided on the organic light emitting structure.   8. The electroluminescent device according to claim 7, wherein the cathode is Ca and Ag.   The electroluminescent device according to claim 7, wherein the anode has a reflective surface. A substrate,
An Al anode provided on the substrate;
A Pt or Ti buffer layer provided on the anode;
A non-metallic layer of ITO provided on the buffer layer;
A fluorocarbon layer provided on the non-metal layer;
An organic light emitting structure provided on the fluorocarbon layer;
An electroluminescent device comprising a cathode provided on the organic light emitting structure.   A Ti layer is provided between the substrate and the anode, and the organic light-emitting structure is NPB (4,4′-bis- [N- (1-naphthyl) -N-phenylamino] -bi-phenyl). It has a hole transport layer and an electron transport / light-emitting layer of Alq (Tris (8-quinolinolato-N1,08) -aluminum), and the cathode is formed on the electron transport / light-emitting layer and has Ca and MgAg The electroluminescent device according to claim 10.

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